While electric drive fluid pumps are, of course, old and well known, they suffer from various deficiencies. First, electric drive pumps for pumping of paints and similar materials are well known but are generally designed for use in well ventilated environments such as construction. In these environments, the unit is merely plugged into the wall and turned on with an operating pressure selected via a dial by the operator.
Such pumps are not suited for use in hazardous environments and electric drive pumps sold to date in such environments have been very complex mechanisms whereby typically the motor is located at the pump and is connected remotely to a large controller which is in turn connected remotely to a power supply. Often the controller and power supply are designed to be located outside of the hazardous environment and in any case the various modules are always quite substantial in size and complexity. In addition, installation of such products can be quite complex and involved.
Applicant hereby incorporates by reference all material contained in U.S. Ser. No. 07/770,554 filed Oct. 3, 1991 by one of the Applicants of the instant invention. This application has now been issued as U.S. Pat. No. 5,220,259, issued Jun. 15, 1993, and it discloses the DC motor drive system utilized in the present invention.